xref: /openbmc/linux/arch/mips/bcm63xx/cs.c (revision 842ed298)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/errno.h>
11 #include <linux/export.h>
12 #include <linux/spinlock.h>
13 #include <linux/log2.h>
14 #include <bcm63xx_cpu.h>
15 #include <bcm63xx_io.h>
16 #include <bcm63xx_regs.h>
17 #include <bcm63xx_cs.h>
18 
19 static DEFINE_SPINLOCK(bcm63xx_cs_lock);
20 
21 /*
22  * check if given chip select exists
23  */
24 static int is_valid_cs(unsigned int cs)
25 {
26 	if (cs > 6)
27 		return 0;
28 	return 1;
29 }
30 
31 /*
32  * Configure chipselect base address and size (bytes).
33  * Size must be a power of two between 8k and 256M.
34  */
35 int bcm63xx_set_cs_base(unsigned int cs, u32 base, unsigned int size)
36 {
37 	unsigned long flags;
38 	u32 val;
39 
40 	if (!is_valid_cs(cs))
41 		return -EINVAL;
42 
43 	/* sanity check on size */
44 	if (size != roundup_pow_of_two(size))
45 		return -EINVAL;
46 
47 	if (size < 8 * 1024 || size > 256 * 1024 * 1024)
48 		return -EINVAL;
49 
50 	val = (base & MPI_CSBASE_BASE_MASK);
51 	/* 8k => 0 - 256M => 15 */
52 	val |= (ilog2(size) - ilog2(8 * 1024)) << MPI_CSBASE_SIZE_SHIFT;
53 
54 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
55 	bcm_mpi_writel(val, MPI_CSBASE_REG(cs));
56 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
57 
58 	return 0;
59 }
60 
61 EXPORT_SYMBOL(bcm63xx_set_cs_base);
62 
63 /*
64  * configure chipselect timing (ns)
65  */
66 int bcm63xx_set_cs_timing(unsigned int cs, unsigned int wait,
67 			   unsigned int setup, unsigned int hold)
68 {
69 	unsigned long flags;
70 	u32 val;
71 
72 	if (!is_valid_cs(cs))
73 		return -EINVAL;
74 
75 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
76 	val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
77 	val &= ~(MPI_CSCTL_WAIT_MASK);
78 	val &= ~(MPI_CSCTL_SETUP_MASK);
79 	val &= ~(MPI_CSCTL_HOLD_MASK);
80 	val |= wait << MPI_CSCTL_WAIT_SHIFT;
81 	val |= setup << MPI_CSCTL_SETUP_SHIFT;
82 	val |= hold << MPI_CSCTL_HOLD_SHIFT;
83 	bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
84 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
85 
86 	return 0;
87 }
88 
89 EXPORT_SYMBOL(bcm63xx_set_cs_timing);
90 
91 /*
92  * configure other chipselect parameter (data bus size, ...)
93  */
94 int bcm63xx_set_cs_param(unsigned int cs, u32 params)
95 {
96 	unsigned long flags;
97 	u32 val;
98 
99 	if (!is_valid_cs(cs))
100 		return -EINVAL;
101 
102 	/* none of this fields apply to pcmcia */
103 	if (cs == MPI_CS_PCMCIA_COMMON ||
104 	    cs == MPI_CS_PCMCIA_ATTR ||
105 	    cs == MPI_CS_PCMCIA_IO)
106 		return -EINVAL;
107 
108 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
109 	val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
110 	val &= ~(MPI_CSCTL_DATA16_MASK);
111 	val &= ~(MPI_CSCTL_SYNCMODE_MASK);
112 	val &= ~(MPI_CSCTL_TSIZE_MASK);
113 	val &= ~(MPI_CSCTL_ENDIANSWAP_MASK);
114 	val |= params;
115 	bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
116 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
117 
118 	return 0;
119 }
120 
121 EXPORT_SYMBOL(bcm63xx_set_cs_param);
122 
123 /*
124  * set cs status (enable/disable)
125  */
126 int bcm63xx_set_cs_status(unsigned int cs, int enable)
127 {
128 	unsigned long flags;
129 	u32 val;
130 
131 	if (!is_valid_cs(cs))
132 		return -EINVAL;
133 
134 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
135 	val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
136 	if (enable)
137 		val |= MPI_CSCTL_ENABLE_MASK;
138 	else
139 		val &= ~MPI_CSCTL_ENABLE_MASK;
140 	bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
141 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
142 	return 0;
143 }
144 
145 EXPORT_SYMBOL(bcm63xx_set_cs_status);
146